nonporous

hard rigid solid stiff sturdy substantial thick tough unyielding

close compact compressed concentrated concrete condensed congealed hardened heavy jelled refractory set solidified

close-grained dense fine-grained impenetrable impermeable impervious inelastic

easy facile flexible nice pliable pliant soft unstable vulnerable weak wobbly yielding

loose

alterable changeable indefinite irresolute moving slack supple unsettled wavering

airtight dense hermetic impassable impervious leak-proof sealed water-resistant waterproof watertight

close close-grained compact compressed concentrated concrete condensed congealed dense fine-grained hard hardened heavy impenetrable impermeable impervious inelastic jelled refractory rigid set solid solidified stiff sturdy substantial thick tough unyielding